How can the 'send_alert' function be customized to send alerts via email?

To customize the send_alert function to send alerts via email, you can use the smtplib library in Python. Below is an example of how you can implement this:

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

def send_alert(subject, message, recipient_email):
    # Email configuration
    sender_email = "your_email@example.com"
    sender_password = "your_password"
    
    # Create the email
    msg = MIMEMultipart()
    msg['From'] = sender_email
    msg['To'] = recipient_email
    msg['Subject'] = subject
    
    # Attach the message
    msg.attach(MIMEText(message, 'plain'))
    
    try:
        # Set up the server
        server = smtplib.SMTP('smtp.example.com', 587)  # Use your SMTP server and port
        server.starttls()  # Upgrade the connection to a secure encrypted SSL/TLS connection
        server.login(sender_email, sender_password)  # Log in to your email account
        
        # Send the email
        server.send_message(msg)
        print("Alert sent successfully!")
    except Exception as e:
        print(f"Failed to send alert: {e}")
    finally:
        server.quit()  # Close the server connection

# Example usage
send_alert("Test Alert", "This is a test alert message.", "recipient@example.com")

Explanation:

1. smtplib: This library is used to send emails using the Simple Mail Transfer Protocol (SMTP).
2. MIMEText and MIMEMultipart: These classes are used to create the email content and structure.
3. Email Configuration: Replace your_email@example.com, your_password, and smtp.example.com with your actual email credentials and SMTP server details.
4. Sending the Email: The function logs into the email server and sends the email to the specified recipient.

Make sure to handle sensitive information like passwords securely and consider using environment variables or secure vaults for production applications.